docs: def send_raw(self, string):
          """Send raw string to the server.
  
          The string will be padded with appropriate CR LF.
          """
          if self.socket is None:
              raise ServerNotConnectedError("Not connected.")
          sender = getattr(self.socket, 'write', self.socket.send)
          try:
              sender(self._prep_message(string))
              log.debug("TO SERVER: %s", string)
          except socket.error:
              # Ouch!
              self.disconnect("Connection reset by peer.")